Infrastructure: Bump geckodriver from 1.20.0 to 1.21.1 (pull #1666)

Bumps [geckodriver](https://github.com/vladikoff/node-geckodriver) from 1.20.0 to 1.21.1.
- [Release notes](https://github.com/vladikoff/node-geckodriver/releases)
- [Commits](webdriverio-community/node-geckodriver@v1.20.0...v1.21.1)

Signed-off-by: dependabot[bot] <support@github.com>

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

package.json

@@ -39,7 +39,7 @@
     "eslint-config-prettier": "^7.0.0",
     "eslint-plugin-ava": "^11.0.0",
     "eslint-plugin-prettier": "^3.3.0",
-    "geckodriver": "^1.20.0",
+    "geckodriver": "^1.21.1",
     "glob": "^7.1.6",
     "htmlhint": "^0.14.2",
     "htmlparser2": "^6.0.0",